Relationship between smoking status and body weight in a military population of young adults.

The purpose of the present study was to determine the association between smoking and body weight in a cohort of young U.S. Air Force recruits (mean age=20 years) enrolled in basic military training (N=35986). Twenty-two percent of recruits smoked daily prior to basic military training (n=8087) and were compared to never smokers, former smokers, and experimental or nondaily smokers. A three-way interaction among smoking status, gender and ethnicity suggested a small effect for daily smoking among White male recruits only and no significant differences for female recruits or members of any other ethnic group. Although there was a statistically significant relationship between smoking and body weight in White males, the effect size was approximately 1 kg. These results suggest that the energy balance differences in body weight between young smokers and nonsmokers are minimal and that it would take decades to accrue the differences typically seen in adult smokers.